The overall objective of this research is the understanding of mechanisms and conditions of occurrence of interactions between peroxidizing lipids and other food constituents especially proteins, amino acids and vitamins. The research is concentrated on interactions occurring in systems simulating dehydrated, intermediate moisture and frozen foods, but the work has implications for other biological systems. The major recent goal has been the elucidation of conditions of production of free radicals in proteins as a result of exposure to peroxidizing lipids. Work planned for next year includes: a) Study of specific end products resulting from free radical reactions of amino acids and amino acid residues in proteing following the initial interaction with peroxidizing lipids. b) Further work on the role of physical distribution of components on rates of reactions between food components especially peroxides of fatty acids and proteins.